...make sure the "base artist" made them themselves from scratch, or had permission to trace whatever they traced to make them. If you can't make sure, assume they didn't have permission.

You may be hurting another artist by using their art against their will. I'm pretty sure none of you want that, but it doesn't seem obvious to many people that those "bases" are more often than not plain rip-offs of existing art.

Just a jaded PSA, sorry, I can't give you a positive message today. It gets me down sometimes what people consider "artists" and "art" and what they consider worth looking up to. I'll snap out of it, I'm just in a funk created by other semi-art-related issues and it makes me extra sensitive.